An activity-based approach for complex travel behaviour modelling

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Oxygen Reduction Reaction at Single-Site Catalysts: A Combined Electrochemical Scanning Tunnelling Microscopy and DFT Investigation on Iron Octaethylporphyrin Chloride on HOPG**

AbstractHere, we investigate the electrochemical activity of a highly oriented pyrolytic graphite (HOPG) supported iron octaethylporphyrin chloride film as a working electrode for the oxygen reduction reaction in 0.1 M HClO4 electrolyte. A voltammetric investigation indicated a quasi‐reversible electron transfer for the FeIII/FeII redox process, which turned out to be responsible for a "redox catalysis like" mechanism, in which the reduction of the metal center is first required to allow the O2 reduction. Here we proved that O2 is mostly reduced to H2O in a tetraelectronic process, as evidenced by a rotating ring‐disk electrode (RRDE). Furthermore, electrochemical scanning tunnelling microscopy (EC‐STM) is used as in operando technique for probing the electrode surface at the atomic level while the oxygen reduction reaction occurs, obtaining information on the molecule adlayer electronic and topographic structures. This allows us to follow the change in redox state from FeIII to FeII induced by the change of the electrode potential in O2 saturated electrolyte. The adsorption of O2 at the iron center was visualized and its depletion upon the application of a potential at which O2 can be reduced. The ORR process catalyzed by FeOEP adsorbed on HOPG was modelled by combining density functional theory, molecular dynamics, and thermodynamics data

Intent Classification in Question-Answering Using LSTM Architectures

Question-answering (QA) is certainly the best known and probably also one of the most complex problem within Natural Language Processing (NLP) and artificial intelligence (AI). Since the complete solution to the problem of finding a generic answer still seems far away, the wisest thing to do is to break down the problem by solving single simpler parts. Assuming a modular approach to the problem, we confine our research to intent classification for an answer, given a question. Through the use of an LSTM network, we show how this type of classification can be approached effectively and efficiently, and how it can be properly used within a basic prototype responder.Comment: Presented at the 2019 Italian Workshop on Neural Networks (WIRN'19) - June 201

An "inherently chiral" 1,1′-bibenzimidazolium additive for enantioselective voltammetry in ionic liquid media

A dialkyl-1,1′-bibenzimidazolium salt, consisting of an atropisomeric dication (i.e. featuring a stereogenic axis and thus "inherently chiral") and an achiral counteranion, is employed as a chiral additive in three commercial ionic liquids, providing successful enantiodiscrimination in voltammetry experiments on screen-printed electrodes (SPEs) with the enantiomers of N,N′-dimethyl-1-ferrocenyl-ethylamine as model chiral probes. Significant differences in redox potentials are observed for the probe enantiomers despite the low concentration (0.01 M) of the chiral additive. The nature of the achiral ionic liquid in which the additive is employed significantly affects the peak potentials and potential differences, but does not alter the enantiomer sequence. Keywords: Chiral electrochemistry and electroanalysis, Ionic liquids, Chiral additives, Inherent chirality, Enantiorecognitio

An Analysis of Word2Vec for the Italian Language

Word representation is fundamental in NLP tasks, because it is precisely from the coding of semantic closeness between words that it is possible to think of teaching a machine to understand text. Despite the spread of word embedding concepts, still few are the achievements in linguistic contexts other than English. In this work, analysing the semantic capacity of the Word2Vec algorithm, an embedding for the Italian language is produced. Parameter setting such as the number of epochs, the size of the context window and the number of negatively backpropagated samples is explored.Comment: Presented at the 2019 Italian Workshop on Neural Networks (WIRN'19) - June 201

Electrocatalytic reduction of bromothiophenes on gold and silver electrodes: An example of synergy in electrocatalysis

The electroreduction of bromothiophenes on Au and Ag provides a striking model of synergy in electrocatalysis, when a second group specifically interacting with the catalytic surface is present besides the reacting one, providing an auxiliary anchoring effect. The high catalytic activity of Ag for bromobenzene reduction is enhanced in the bromothiophene case. Moreover, Au, having for bromobenzene a much lower and less reproducible catalytic effect than Ag on account of the repulsive effect of its very negative surface charge in the working potential range, approaches Ag activity in the case of 2-bromothiophene, where the anchoring S group is adjacent to the Br group to be cleaved. The beneficial anchoring effect is lower when it has to be shared between two Br leaving groups adjacent to the S group, and becomes negligible in the case of a bromide leaving group in 3-position. Keywords: Molecular electrocatalysis, Dissociative electron transfer, Anchoring groups, Bromothiophenes, Gold electrodes, Silver electrode

Guided resonances in photonic crystals with point-defected aperiodically-ordered supercells

In this paper, we study the excitation of guided resonances (GRs) in photonic-crystal slabs based on point-defected aperiodically-ordered supercells. With specific reference to perforated-slab structures and the Ammann-Beenker octagonal lattice geometry, we carry out full-wave numerical studies of the plane-wave responses and of the underlying modal structures, which illustrate the representative effects induced by the introduction of symmetry-preserving and symmetry-breaking defects. Our results demonstrate that breaking the supercell mirror symmetries via the judicious introduction of point-defects enables for the excitation of otherwise uncoupled GRs, with control on the symmetry properties of their field distributions, thereby constituting an attractive alternative to those GR-engineering approaches based on the asymmetrization of the hole shape. In this framework, aperiodically-ordered supercells seem to be inherently suited, in view of the variety of inequivalent defect sites that they can offer.Comment: 13 pages, 12 figures, 1 table. Slight change in the title; major changes in the text and figure

Inhibition of Stearoyl-CoA desaturase 1 reverts BRAF and MEK inhibition-induced selection of cancer stem cells in BRAF-mutated melanoma

Combination therapy with BRAF and MEK inhibitors significantly improves survival in BRAF mutated melanoma patients but is unable to prevent disease recurrence due to the emergence of drug resistance. Cancer stem cells (CSCs) have been involved in these long-term treatment failures. We previously reported in lung cancer that CSCs maintenance is due to altered lipid metabolism and dependent upon Stearoyl-CoA-desaturase (SCD1)-mediated upregulation of YAP and TAZ. On this ground, we investigated the role of SCD1 in melanoma CSCs

What’s the best assessment of preload after cardiac surgery?

Objective: The assessment of the role of transesophageal echocardiography and invasive tests with pulmonary modified catheter to monitor the preload indexes in patients in intensive- care-unit after cardiac coronary surgery. Materials and Methods: Between January and December 2004 24 patients (14 male, 10 female) with coronary artery disease were prospectively enrolled for preload assessment during off-pump myocardial revascularization. Pulmonary Capillary Wedge Pressure (PCWP), Left Ventricular End Diastolic Indexed Area (LVEDAI), Δ Aortic Velocity (ΔVAo), Right Ventricular End Diastolic Volume (RVEDVI) as preload indexes were evaluated. Transesophageal echocardiography and pulmonary modified catheter monitoring were performed during the preoperative period at T1 and after fluid infusion (T2). Patients were considered Responders (R) or No Responders (NR) if the Stroke Volume Index increase at T2 was >20% with respect to T1. Results: Mean T1 PCWP was similar in both groups (12.8±2.2 in R vs. 11.4±3 mmHg in NR; p=NS) and mean increase of PCWP at T2 was similar in both groups (1.5±0.3% in R vs. 1.2±3% in NR; p=NS). Mean T1 RVEDVI was similar in both groups (97.33±34 in R vs. 101±21 ml/m2 in NR; p=NS); T2 RVEDVI was similar in R and NR Groups (122.11±49 vs. 138.54±30 ml/m2; p=NS); mean T1 and T2 LVEDAI was similar in R and NR (11.2±3.5 vs. 10.2±2.3 at T1 and 14.04±3.35 vs. 14.67±2.1 cm2/m2 at T2 respectively; p=NS). Higher mean value of T1 ΔVAo (20±7% in R vs. 10±2% in NR; p=0.006) were recorded while similar mean value of T2 ΔVAo were observed (11±3% in R vs. 5±2% in NR; p=0.743). Correlation index between T1 and T2 ΔVAo (R=0.82) in R was significant (p=0.0002), while correlation index between T1 and T2 ΔVAo (R=0.11) in NR was not significant. Conclusions: Our study showed in patients soon after coronary cardiac surgery ΔVAo is the only predictor of “fluid responsiveness” and of ventricular compliance

The First Collective Examination of Immunosuppressive Practices Among American Intestinal Transplant Centers

BACKGROUND: Unlike other solid organs, no standardized treatment algorithms exist for intestinal transplantation (ITx). We established a consortium of American ITx centers to evaluate current practices. METHODS: All American centers performing ITx during the past 3 y were invited to participate. As a consortium, we generated questions to evaluate and collect data from each institution. The data were compiled and analyzed. RESULTS: Ten centers participated, performing 211 ITx during the past 3 y (range, 3-46; mean 21.1). Induction regimens varied widely. Thymoglobulin was the most common, used in the plurality of patients (85/211; 40.3%), but there was no consensus regimen. Similarly, regimens for the treatment of acute cellular rejection, antibody-mediated rejection, and graft-versus-host disease varied significantly between centers. We also evaluated differences in maintenance immunosuppression protocols, desensitization regimens, mammalian target of rapamycin use, antimetabolite use, and posttransplantation surveillance practices. Maintenance tacrolimus levels, stoma presence, and scoping frequency were not associated with differences in rejection events. Definitive association between treatments and outcomes, including graft and patient survival, was not the intention of this initial collaboration and is prevented by the lack of patient-level data and the presence of confounders. However, we identified trends regarding rejection episodes after various induction strategies that require further investigation in our subsequent collaborations. CONCLUSIONS: This initial collaboration reveals the extreme heterogeneity of practices among American ITx centers. Future collaboration will explore patient-level data, stratified by age and transplant type (isolated intestine versus multivisceral), to explore the association between treatment regimens and outcomes